Sewing mechanism



June 17, 1947. M. PEDERSEN SEWING MECHANISM Filed May 21, 1945 3 Sheets-Sheet 1 INvNToR MATHlAs PEDERSEN ATTORNEY June 17, 1947. M. PEDERSEN SEWING MECHANISM Filed May 21, 194s 5 Sheets-Sheet 2 l Wm Vl m M M www mmm n mm A HUI Ml @my @N Kw Mm Q m, i .m u, www L@ 1\ L wm www ,/-L LUV ifwwiiizr K @N Sw n @w @Nw aww @N .iwf -mrrr N@ ww M. PEDERSEN 2,422,208

SEWING MEGHANISM June 17, 1947.

5 shets-sheet 3 Filed May 2l, 1943 3f f3 265J 2 2 7 2502/5 27/ INVENTOR MATHIAS PEDERSEN BY f ATroRNEY Patented June 17, 1947 SEWING MECHANISM Mathias Pedersen, Brooklyn, N. Y., assignor to American Machine and Foundry Company, corporation of New Jersey Y Application May 21, 1943, Serial No. 487,850

9 Claims.

This invention relates to sewing machines, and more particularly to improvements in sewing machines of the type employing a double pointed needle having an eye located between the points, and means for projecting the needle back and forth through the material to be sewed in order to form over and under stitches therein.

In machines of this type which operate with a relatively short length of thread, it is advisable to provide some means for supporting the thread at all times so that slack is so controlled as to make it practically impossible for the thread to be improperly positioned during the operation of the machine. With certain types of thread now available, the problem of slack control between the throat plate of the machine and the lower needle bar has become increasingly difficult of solution due to the manner in which the thread behaves in handling. Thread such as cotton or combinations of cotton and rayon, or other composite threads have a tendency to twist and bend unless subjected to positive mechanical control and hence are likely to be split or pierced by the needle, or broken 1by moving parts of the machine with which they engage. It is, therefore, an object of my invention to provide improved mechanism for eifecting a more positive control of the thread in a sewing machine. j

It is a further object ofA my invention to provide novel thread supporting and guiding mechanism which contributes to the increased eiliciency of an under and over type sewing machine. In some instances slack formed in thread by a tension finger member acting in conjunction with a thread trap has tended to drop, or twist and bend downwardly into engagement with the rear loop of thread located beneath the throat plate of a machine to such an extent that this loop was biased out of proper position and so located that the thread puller would engage both the front and mispositioned rear loop and cause thread breakage.

It is a further object of my invention to provide a novel thread supporting and guiding device for effecting more positive control and support of slack thread than heretofore known.

It is an added object of my invention to provide an auxiliary thread supporting and guiding mechanism which effectively prevents slack thread from dropping into engagement with a loop portion of the thread where it can press the loop portion out of proper arrangement with the thread pulling means. In this manner my invention substantially eliminates excessive thread breakage during the operation of the machine.

My invention also consists in the provision of an improved thread guide and slack support which coacts with a thread shifting or tension nger and thread trap, and assists in supporting the thread out of the path of the needle and maintaining the same disposed properly during the sewing operations.

With these and other objects not specifically mentioned in View, the invention consists in certain combinations and constructions which will be hereinafter fully described, and then Set forth in the claims hereunto appended.

In the accompanying drawings, which form a part of this specification, and wherein the several reference characters designate the same or like elements:

Figure 1 is a side view of a sewing machine of I the short thread type, parts being broken away to show the mechanism forming the novel thread supporting device; Y

Figure 2 is a perspective View of the improved thread supporting and guiding device;

Figure 3 is a partial plan View showing the improved thread guide and support device mounted for use in conjunction with the thread tension mechanism;

Figure 4 is a side View, the same taken from line 4-4 of Figure 3;

Figure 5 is a front View showing a part of the thread tensioning and guiding mechanism;

Figure 6 is a View showing the manner in which the thread is supported during the operation of the thread tensioning mechanism;

Figure 7 is a plan View of the same; and

Figure 8 is a partial perspective view showing the coaction between the tension linger and slack supporting member.

Referring to the drawings, the sewing machine which is of the same general type as that shown in co-pending application, Serial No. 355,738, filed September 7, 1940, by C. W. Johnson, which has matured into patent, No. 2,386,800, October 16, 1945, includes a center support 30 and a combination frame and housing 3|, the frames being secured to and spaced by supporting members 32 which in turn are mounted on the machine pedestal (not shown). Frame 30 supports a bracket 34 carrying the forward end of the sewing machine table 35, the rear end of same being secured to blocks 36 fastened to frame 3l.

A pulley 3l is driven by a belt 38 which also runs over a pulley (not shown) associated with a clutch and brake mechanism driven from a motor (not shown) in the same manner as disclosed in the above referred to co-pending application.

4 mentarily. The needle bar 63 then moves down slightly and dwells, and in so doing forms a loop in the thread. Substantially simultaneously the looper arm |8| and finger |84 advance in unison; arm |8| engages the front part of the loop while nger |84 engages the rear part of the loop (see Y Figures 6 and 8), both arm and finger continuing 64 in proper timed relation tov project a needle" back and forth through work being sewed.

The upper needle bar operating unit consists of a lever formed with a hub or sleeve 50 pivotally mounted on shaft (not shown) supported at one end in a hub 54 of a bracketl 55 securedl to wall Y a cam follower (not shown).traveling in the track yof cam 39.. Needle bars 63, lie are provided with suitable actuator members S engaged by lever arms-.66 and 61 at the forward ends of their respectiveoscillatinglevers, whereby to convert the oscillating motion of the llevers effected by cam 39, into vertical reciprocating motion of the needle bars.' Since the specic mechanism for operating the needlebars forms no part of this invention, lfurther disclosure and description thereof `is deemed unnecessary and omitted.

Material to be sewed is positioned for sewing in the usual manner and is guided by the operator over table 35 mounted on bracket 34 as disclosed inv the above referred to co-pending Johnson application. A presser foot |20, used in conjunctionY with feeding foot |2I, and a feed plate |22V attached to a cam actuated arm |23, is provided'to engage and retain the work in position Y and past the needle.

A looper cam' |10 secured to hub 40 of gear 4| (Figure 1) engages a cam roller |1| mounted on a stud |12 carried by lever |13 fastened to cross l shaft 11d-extending through bridge 51. By means of cam looper arm ISI, fixed Jto-shaft |14 and provided with a pointed finger |82 (Figures 6 and 8), and thread guide roller |83 is operated in conjunction with a tension finger |84 which is 'also'mounted on shaft |14 and is operative to move with arm |8| by means of a friction connection (not shown) into and out of engagement with a portion ofthe thread adjacent the opposite side of the needle, as shown in Figure 8.

When the needle is transferred from the lower needle bar 64 to the upper needle bar` 63,l the latter grasps the needle and ascends under the actionof its cam actuatedl lever 50 to its up-position. The looper arm |8| by'means of cam |10 is movedt'owards linger |84 as soon as the needle bar-'63 has-ascended sufficiently to permit it to -epass,` the arm I8| continuing to travel until pointed finger |82 is approximately in` alignment with finger |84 Vin which'position it dwells-mo- V53,' providedv with an arm (not shown) mounting Y to advance and pull the thread'in order to provide suflicient slack and support the thread properly above and relative to the material being sewed, and the needle. is then stopped by suitable mechanism (not shown) similar to that disclosed in said Johnson application,while arm |8| continues its full swing to the position shown in Figures 6 and 8. Arm

V|8| then retracts, whereupon needle bar 63 descendsand in so doing a cam carried by the needle bar (not shown) moves nger |815 back to its inoperative position (not shown). The needle bar 63 and arm |85 complete their travel, it being understood that the needle has passed'through the workand is now gripped in the lower needle bar 64, the upper needle bar 63, looper |8| and ringer |84 retaining their inoperative positions until the needle is again transferred to the upper needle bar. Y

With needle 8|V gripped in lower` needle bar 64, the latter descends under the action of camV actuated lever 5| to down-position at the same time pulling the thread partly through the Work whereupon the needle bar immediately ascends slightly and dwells. This slightmovement upward tends to form a loop in the thread beneath work table 35 and throat plate 216 mountedlon the underside of table 35. Plate 216 is provided with an irregular opening and thread guide 211 through which the needle may move and in which the thread is guided laterally relative Vto the needle by means described hereinafter. While the bar 64 dwells a pair of cam actuated gripper arms 200,. 20| (Figures 1 and 5) constructed and operated` in the manner set forth in the above referred to Johnson application close around the needle and looped portion of the thread to prevent unnecessary pulling of the thread as the thread puller 202 enters theffront part of the loop and starts to pull the free end of theY thread through theV work, as disclosed in said Johnson application. Grippers 200,1201 are operated by aV cam 203 adjustably attached to a cam 204 on cam shaft 205 driven by gear 226. By means of a cam follower 206 on lever 201 engaging a track |99 in cam 203 at appropriate times during each cycle of the machine, jaws 200, 20| close upon a portion of the thread extending between theneedle held infneedle bar 64 and the work, and prevent excess tension thereon when the thread puller 202 is" pulling the loose end of the thread through the work. Y v

Lever 201 is mounted on stud 208 carried by holder 209 fastened to support 2|0 attached to frame 30. The upper endrof arm-201'(Figure 5) is provided with a yoke 2| adapted-to engage a pin 2|2Von a bar 2|3 sliding in a runway 2|4 in block 2|5. The oscillation of lever 201'reciprocates bar 2|3 provided jwith inclined slots therein (not shown) coacting vwith rollers on arms 200, 20|. rIhese arms are opened and closed in the same manner as described and villustrated inl the above referred toco-pending Johnson application. Amore detailed disclosure of "this arrangement is, therefore, Ydeemed unnecessary in'thepresent application. K

Thread puller 202 is rotated by inea-ns'of .1a crank mechanism including carn roller 243 on Movement of nger |811y crank arm 244 lixed to shaft 245 engaging spaced bars 240, 24| carried by gear 232 suitably driven from gear 4|. Thread puller 202 is rotated With varying speeds so that its action is to engage the loop of thread while moving slowly, after which it pulls the loose end of the thread through the work with gradually increasing speed from approximately the time it picks up the thread until it again approaches the pick-up position, whereupon its advancing movement is gradually retarded.

Coacting with the needle bars, needle and thread puller, and acting to tension the thread properly and also prevent thread fouling or splitting by the needle is a linger 241 (Figures 3 to 8, inclusive). In the illustrated embodiment linger 241 is provided with a hook at its free end to engage and pull the thread out of the path of the needle as it moves back and forth through the work. At the time of transfer of the needle from one bar to another, the thread is held out of the path of the needle so that the thread is always clear of the needle and properly tensioned. The motion of linger 241 is controlled by suitable cams 248, 249 mounted on a vertical shaft 250 driven by means of helical gears 253, 254 (Figure 1), the latter lixed on shaft 265 supported in housing 25| of a bracket 252, this mechanism operating in the same manner as shown and described in said co-pending Johnson application referred to hereinabove. Finger 241 preferably is adjustably clamped in a head 264 (Figure 3) which through said gears and cams is moved in a closed path into and out of engagement with the thread engaged thereby.

A helical gear 253 lixed to the lower end of shaft 250 meshes with a similar gear 254 on shaft 205. Cam 248 (Figure 5) enga-ges a cam follower 255 on arm 256 loosely mounted on a stud-251 carried by a lug 258 on bracket 252. Arm 256 also supports a link 259 having an elongated slot (not shown) in which moves a stud (not shown) on an arm (not shown) lforming a part of the operating means of tension linger 241. This last mentioned arm is attached to the lower end of a stud 26| (Figure 5) loosely mounted in a bearing 262 at the free end of a lever 263, the stud 26| terminating in a head 264 in which linger 241 is adjustably clamped. Any suitable means, such as a screw (not shown) may be .provided to permit of adjustment of linger 241 in any desired position to engage the thread properly. A spring 261 is connected to arm 250 and has its other end attached to an adjustable rod (not shown) to allow the spring to be tightened or loosened as desired.

A second cam '249 on shaft 255 engages a cam roller 268 on an arm 269 which is connected with the lever 263, the lever unit being loosely mounted on a stud 216 carried by lug 258. A tension spring 21| stretching between posts on levers 263 and arm 256 acts to hold cam followers 255 and 268 in engagement with their respective cams. Through the action of cams 248, 249, linger 241 is given a movement about the axis of stud 26| effected by the arm 266 and is also displaced together with stud 26| by lever 263. The construction and operation of the tension linger actuating mechanism is similar to that described and shown in the above referred to Johnson application.

VFinger 241 coacts with a guide plate 215 fastened to a throat plate 216 (Figures 3 and 4) the guide plate being provided with an irregular opening 211 tending to guide the thread within the path of linger 241 which may describe a closed path of movement in a single direction corresponding somewhat to the contour of the opening, the finger remaining stationary for a time at a point in the path. In being so operated the hooked end of the linger 241 moves to engage the thread and pull the same laterally from one side of the needle path (see Figures 3 and 7), the linger holding and tensioning the thread in that position while the needle reciprocates.

Acting in conjunction with tension nger 241 and guide plate 215 is a thread slack supporting member designated generally 36B. As described hereinabove, this member forms an important feature of the present invention and contributes to the efficiency and operation of the machine by overcoming the tendency of threads to twist and bend out of desired positions relative to the needle.

In the form selected for illustrative purposes, slack supporting member 3U!! consists of a bar 35| (Figure 2) having holes 362 accommodating screws 364 which secure the member to block 2I5 (Figures 1, 3 and 5). Mounted on and suitably secured to bar 36| is a plate 306 having a narrow elongated neck 368 extending therefrom. Neck 358 is bent into a hook thread support or rest 652 having an upwardly extending thread guide face SI2 so that during the movement of needle bar 54 and grippers 288, 289 upwardly, and operation of tension linger 241. face 3|2 acts to direct the thread along thread guide face 3|2 into hook thread support 3H) Where said thread remains held out of the path of the needle and properly disposed to prevent interference with the loop about to be formed while supported by member 360.

As shown in Figures 1 and 5, the elongated neck 368 is preferably formed with a U-shaped part which permits feed bar support |23 to move therebeneath (Figure fi). Referring to Figures 5, 6, '1 and 8, it will be seen that plate 366 is so mounted on bar 36| that hook thread support 3H! is positioned adjacent the path of movement of needle 2| and lower needle bar 64. The upwardly inclined face 3|2 of support 3|0 is shaped in such a way that when the lower needle bar 64, and the lateral thread displacing grippers 283, 285 move upwardly, face 3l2 actually acts as a cam, and guides the slack thread into hook support 3|!l where it remains until thread puller 202 pulls the loose end of the thread through the work and disposes the same about drum 224. At the same time the thread is being located in hook support 3|0 another portion thereof is disposed in thread trap 3 l 6 by grippers 288, 289.

Thread trap 3l6 acts both as a trap t0 catch the thread, as a result of the upward swinging movement of grippers 288, 289, and also performs the function of a stripper to prevent thread from moving with the grippers as they return to thread receiving position (Figures 1 and 5).

Slack supporting member 306 which is located adjacent the lovver needle bar 64 and beneath plate 215 insures that the slack thread shall at substantially all times be positioned above the bar out of the path of the needle and looped thread. In operation as needle bar 63 descends, tension linger 241 moves along the closed path shown in dotted lines in Figure 3 into engagement with the thread and displaces the same out of the path of the needle. At the same time.

linger 241 tensions and forms slack in the thread (Figure 8). As needle 8| is gripped by bar 64,

tioned pathV (Figure 3), the slack thread is released. Due to the presence Yof slack support 30 the slack thread has been guided along face SI2 and disposed? in hook 3HE, and hence is SuDDOIted positively out of engagement with the rear loop of thread formed as a result of the upward movement of bar 64. In this manner the rear loop of thread is not subjected to movement by dropping or twisted slack out of its proper relation to the thread puller 202, and breakage of thread because of improperly positioned loops'is substantially eliminated. In the same manner slack thread is positively supported and held out ofthe path of movement of the needle and out of Ythe path of the rotatingV thread puller 202. rIhe operation of this device therefore is effective in greatly decreasing and substantially eliminating breakage of thread.

The sewing operations of iinger 24?, grippers 288, 289, needle bars 63l and Bd, work feeding member H2B, 24, and 23, and associated ele' ments are substantially the same as those described inV said Johnson application.

The cam 204 (Figure 1) is provided with a cam track 280 engaging a cam roller 28| of a trip arm 282 mounted on a stud 283 carried by a lug (not shown). The upper end of arm 232 engages the end of a plug 285 which is secured to the end of a spring tensioned rod 285 which terminates at its other end in a member 281 having a vertically extending jaw portion 288. The pointed part 289 of a swingable arm 290 together with the jaw portion 288 form a gripper cr clamp adapted to clamp the thread and later carry the same upward. The plug 28-5 and rod 28S slide in suitable apertures provided in the arm 29] and a spring (not shown), an aperture in the arm 290 tends normally to hold the plug 285 against the end of arm 282. The swinging motion of arm 29B, is effected by the cam 220 on shaft 255 which has a cam track 292 engaging a cam roller 293 of a cam lever 29d loosely mounted on a stud 295 carried by a lug (not shown) of the member 62. Lever 294 at its upper end supports a head 291 carrying a rod 298 connected to a depending lug 299 of the arm 29S which is mounted on a stud 320 carried by theb-lock 215.

The invention above described may be varied in' construction within the scope of the claims, for the particular device selected to illustrate the invention, isbut one of many possible concrete embodiments of the same. It is not, therefore, to be restricted'to the ,precise details ofthe struc'- tureshown and described.

What is claimedl is:

1. In asewing machine of the type having opposed needle bars constructed and arranged to project a double pointed needle and a thread back and forth through material to be sewed, and a thread trap; a thread guiding and tensioning device adapted to move thread out of the path of said needle, and a stationary thread guide, means mounting said guide proximate the path of said needle andbetween said device and said trap, said guide being constructed and arranged to coact with said deviceV for supporting a. portion of said thread clearof the needle.

In a sewing machine` of the type having opposed needle barsA constructed and arranged to project a double pointed needle having a thread with a loose and a Y:fixed end. back and forth through material to be sewed, a thread trap, and

grippers for transferring a portion of the'rloose end ofthe thread'into said trap; a thread guide support, and Vmeans mountingsaid support between saidtrap-and one ofsaid bars for receiving and supporting-slack thread disposed therein as the result of the thread transfer operation of said? grippers and` upward movement of one of said bars.

3; In asewing machine having opposed needle ba-rs'a'nd means for operating said bars to project a needle and al thread back and forththrough work tobe sewed, including means forv forming a loop in said thread adjacent one of said bars, a f

thread trap, and means forforming slack'in another portion of said thread; a stationary thread slack supporting device, means mounting said device adjacent said one ofy said bars; and means for transferring a portion of said thread into said tra-p and locating said slack in said device clear of the path of Vmovement of said needle.

4. InA a sewing machine of the type having' opposed needle bars constructed and arranged to project a double pointed needle having a thread with arloose' and a fixed end back and-'forth through material to be sewed including means for moving one of said bars towards said material to form loop portions in saidr thread on'oppo'- site sides of said needle, a thread puller, and means Vfor moving said pullerV into engagement with one of said loop portions to pull the loose endv of said thread through said work; a thread trap, means for transferring a portion of lsaid loose end of said thread into said trap, and a bar, saidmember being constructed and arranged to receive slack thread as the result of the transier of threadr into said trap, and thereby support said slack threadY clear of the needle.

5. In a sewing machine of the type described having VaY work table, upper Yand lower opposed needle bars positioned above and below said table, and means for operating said bars to project a needle and a thread having a xed and a loose end back and forth through workA on 'said table, a thread looper mounted above said table, `and operable to'support a portion of the loose end of the thread above the work table and a device operable in timed relation with said looper for forming slack in said loose end portion of said Ythread and moving said thread laterally outof the path of movementy of saidj needle, and a proximate said lower needle bar, and a hook on said member adapted to receiveV andsupport said slack threadv clear of the pathof movement of said puller. A

6. In a sewing machine having opposed upper and lower needle bars and means for reciprocating said bars toV project a needleV and a thread having a loose end and a nxed end back and forth through material to be sewed, a thread displacing device, and a traveling thread puller, means mounting said puller on one side of said needle and bars for movement into engagement with a portion of said thread to pull saidr 10.056 end of said thread through said material; a slack threadV supporting member including a V-shaped portion provided with an upwardly directed guide surface, means mounting said member in thread receiving position adjacent said lower bar mechanism for moving said lower needle bar and said ranged'to support said slack-thread clear ofthe 9 paths of movement of said needle and said thread puller.

7. A slack thread supporting member for a sewing machine of the type utilizing opposed needle bars, and a double pointed needle, :comprising a support member, an elongated portion extending outwardly from said member, a slack thread support formed in said portion, and a thread guide face formed on said support, said support being formed for mounting thereof in thread supporting position adjacent one of said bars.

8. A slack thread supporting member for a sewing machine of the type utilizing opposed needle bars, and a double pointed needle, a narrow elongated substantially horizontal neck extending outwardly substantially at right angles to the body of said member, a hook formed adjacent the end of said neck, and an upwardly directed thread guide surface forming a part of said hook, said surface being constructed and arranged to guide slack thread into said hook, said support being formed for mounting thereof in thread sup porting position adjacent one of said bars.

9. In a sewing machine having upper and lower opposed needle bars, means for operating said bars to project a needle and a thread having a loose and a iixed end back and forth through work to be sewed, and a thread puller for pulling the loose end of the thread through the Work and disposing the same about a thread receiving drum, a work supporting table over which Work to be sewed is moved past said needle, a thread trap located beneath said table, and thread grippers for moving a portion of the loose end of thread disposed about the drum into said trap, said trap having means for stripping said thread from said grippers; a slack thread supporting member mounted beneath said table and provided with a slack thread support located between said trap and said lower needle bar, said member being constructed and arranged to coact with said trap and hold said slack thread clear of the paths oi movement of said needle and said thread puller.

MATHIAS PEDERSEN.

REFERENCES CITED UNITED STATES PATENTS Name Date Forman June 11, 1918 Number 

